Strikers along Poland's Baltic Coast returned to work today, but miners in the vital silesian coal mines continued their walkout. The country's communist government, meanwhile, began defending its decision to allow the establishment of free trade unions and showed its good faith by releasing about 30 imprisoned dissidents.

Some Polish officials privately expressed concern at a commentary in the Soviet Communist Party newspaper Pravda that was widely interpreted as a criticism of the strike settlement. Despite the Kremlin's objections. Polish authorities have very little room for maneuver as any attempt to roll back on the agreement would undoubtedly trigger off a fresh round of labor unrest.

Workers in other Polish cities, including the industrial centers of Wroclaw and Lodz in the southwest, have already secured government concessions to match those granted to the strikers on the northern Baltic Coast. Today, the government confirmed that about 30,000 miners and steel-workers in the Katowice region of southern Poland, the country's industrial heartland, have also been on strike for the last three days.

The official Polish news agency said late Monday night that a tentative agreement had been reached with at least some of the strikers in the mines, news services reported. There were no reports from the miners, however, and it was unclear if the agreement would include all the workers in the Silesian region.

[It was also uncertain when the agreement would take effect, if it is approved.]

The miners' strike there represents a further damaging blow to the personal authority of Poland's Communist Party chief, Edward Gierek. It was in Katowice that he made his early political career, and at one time he enjoyed considerable popularity among Silesian workers.

Meanwhile, the government gave way to yet another of the strikers' demands by releasing around 30 dissidents who have been held in detention for the last two weeks. Those released include Jacek Kuron, spokesman for the Workers' Defense Committee (known from its initials in Polish as KOR), and Jan Lytinski, editor of the underground newspaper Robotnik, which provided detailed information about the strikes.

Along with many of their supporters, both men had been served with a prosecutor's warrant under which they could have been held for up to three months on suspicion of forming a criminal organization.

In newspaper editorials today, the Polish press hailed the agreements signed with strike leaders in the ports of Gdansk and Szczecin over the weekend as "a sensible compromise." The Warsaw daily Zycie Warszawa said the settlement would help "correct past errors and create conditions for the reconstruction of ties between society and the authorities."

The Polish press comment appeared at least partially aimed at persuading the Kremlin that the standing of the Polish Communist Party in national life could be strengthened rather than weakened as a result of the settlement.

A passage in an editorial of the Communist Party daily newspaper Trybuna Ludu rebutted accusations in Pravda of links between the strike leaders and subversive elements abroad. The paper agreed that what it described as "antisocialist forces" had exploited the conflict for political ends, but added: "The signed agreements limit the opportunities for opponents of Poland to interfere in the difficult discussion of our problems."

The return to work along the Baltic Coast took place on a windswept day. As the strikers streamed back through the open gates of some 700 plants, many expressed happiness over the outcome of the dispute.

There was a festive atmosphere at the Lenin Shipyard, the strike's center and the site of negotiations between the government and workers' representatives over the past week. But there were no open celebrations in the streets of Gdansk, and police patrols were reported to have been reinforced during the night.

Meanwhile, the leader of the Gdansk strikers, Lech Walesa, formally opened the new headquarters of the independent trade union movement in an apartment on the outskirts of that city donated by the authorities. His first act was to hang up the crucifix that had decorated the hall of the shipyard where delegates to the interfactory strike committee met.

The unfurnished apartment, which formerly belonged to a doctor, was made available to the new union as temporary accomodations until larger premises are found.

Questioned by foreign reporters about the attack on strike leaders carried by Pravda, Walesa replied: "I am not concerned with politics, my business is trade union organization."

In Warsaw this evening, Workers' Defense Committee detainees who were released, held a makeshift press conference in Kuron's apartment. Kuron, who has himself been detained on some 70 different occasions, welcomed the settlement as "a victory for realism."

"The agreement to set up new independent unions has increased the realm of freedom and lessened that of totalitarian power, while at the same time assuring that we don't attract Somviet tanks across the border," he said. t

Senior Communist Party officials have expressed determination to strictly abide by the terms of the agreement reached with the strikers in Gdansk and Szczecin. One member of the policy-making Central Committee commented privately: "If we don't follow the terms, there'll be a new wave of strikes or a catastrophe. We must follow them step by step."

A goverment spokesman said a further extraordinary session of the Central Committee would be held in the near future to analyze in greater depth the causes of the crisis. He also said that the agreements reached along the Baltic would apply nationwide.

Officials said that, in view of the government's flexible attitude, it was hoped that the strikes in Silesia would be settled swiftly. A government commission has already begun detailed negotiations with the strikers, and have reached provisional agreement on many of their demands.

Tonight, television and radio stations throughout Poland broadcast the full text of the communique issued by the government commission and the strike committee in Gdansk. The statement, which took about 20 minutes to read out, listed each of the strikers' 21 demands and then the final settlement agreed upon by the two sides.